Magnesium Glycinate vs Oxide — Which Form Actually Works
Complete magnesium form comparison 2026 — glycinate vs oxide vs citrate vs malate, real absorption percentages, stomach tolerance, who needs which form, and exactly which magnesium to buy in Sweden. Facts, not label copy.
Magnesium glycinate vs oxide in 30 seconds
Magnesium oxide is the cheapest form on shelf. It's also the worst-absorbed — roughly 4% of the elemental magnesium actually enters your bloodstream. Magnesium glycinate absorbs at ~40%, roughly ten times better, and rarely causes the GI distress oxide is infamous for. If a product lists "magnesium 375 mg" but doesn't specify the form, it's almost always oxide.
Heey!'s Rest & Recover is a 100% vegan magnesium complex (bisglycinate + citrate + taurate + malate) with 3000 mg glycine plus zinc, chamomile, and lemon balm. 259 kr per pouch (30 servings), Strawberry Lemonade, made in Sweden, no added sugar. URL: itsheey.com/products/rest-recover-magnesium.
The short rule: for sleep, stress, and daily use pick glycinate (or bisglycinate — same thing). For constipation relief pick citrate or oxide. For training recovery pick malate or glycinate. Oxide alone is rarely the right answer.
The four forms that actually matter — absorption compared
Every supplement-grade magnesium is magnesium bonded to something. That "something" determines how well your gut absorbs it and how your stomach handles it. Cheap forms bond to small cheap molecules. Expensive forms bond to amino acids that escort the magnesium across the gut wall.
| Form | Approx. absorption | Stomach tolerance | Best use |
|---|---|---|---|
| Magnesium glycinate / bisglycinate | ~40% | Excellent — no laxative effect at normal doses | Sleep, stress, anxiety, daily use, higher doses |
| Magnesium citrate | ~25-30% | Mild laxative effect at higher doses | General use, mild constipation relief, budget option |
| Magnesium malate | ~25-30% | Good — rarely causes GI issues | Muscle recovery, fatigue, fibromyalgia context |
| Magnesium oxide | ~4% | Poor — often causes diarrhea and cramping | Short-term constipation relief only |
The absorption gap is not marketing — it's measured. A 2003 study in Magnesium Research compared plasma magnesium after oral dosing and found oxide absorbed at roughly one tenth the rate of organic magnesium salts. The 2019 Nutrients review on magnesium bioavailability reaches the same conclusion: oxide is a functional laxative dressed up as a supplement.
Why oxide still dominates store shelves
Oxide is cheap to manufacture and contains the highest percentage of elemental magnesium by weight. A 400 mg magnesium oxide tablet is ~60% elemental magnesium (240 mg on the label). The same weight of glycinate is only ~12% elemental magnesium. Label math favors oxide, so brands pile it on and print a big number.
The problem: elemental magnesium on a label doesn't equal magnesium in your bloodstream. 240 mg of oxide delivers ~10 mg absorbed. 100 mg of glycinate delivers ~40 mg absorbed. The smaller "on paper" dose is the larger real-world dose.
Watch for these warning signs on a magnesium label:
- "Magnesium 375 mg" with no form specified — almost always oxide
- Very low price per mg elemental — reflects oxide's cheap production
- "Supports bowel regularity" phrased as a feature — it's actually admitting the oxide laxative effect
- Tablets the size of a horse pill — usually packed with oxide plus fillers
Who needs which form
- Sleep trouble or nighttime wake-ups: glycinate. The glycine co-factor has mild GABAergic effects that pair with the magnesium for a calming profile. 200-400 mg elemental magnesium as glycinate, 30-60 min before bed.
- Stress, anxiety, overstimulation: glycinate. Same reason — calming amino acid partner, no GI disruption during the day.
- Muscle cramps, twitches, post-training recovery: glycinate or malate. Malate has a theoretical advantage via the Krebs-cycle malate component for energy metabolism.
- Constipation: citrate at 200-400 mg, or short-term oxide. Here the poor absorption is the point — undigested magnesium draws water into the colon.
- Migraine prevention: glycinate or citrate at 400-600 mg elemental, under clinician guidance. American Academy of Neurology lists magnesium as a Level B preventive.
- Elderly or low stomach acid: glycinate. Oxide requires adequate stomach acid to dissociate — absorption drops further on PPIs or with age.
The complete sleep stack, why Heey! combines forms
Magnesium bisglycinate alone is already well-studied for sleep. Heey! Rest & Recover layers three additional magnesium forms (citrate, taurate, malate) plus added cofactors that each target a different sleep-related pathway in the same evening dose.
The stack targets multiple pathways in one routine:
- Magnesium bisglycinate supports muscle relaxation and nervous-system calming via NMDA receptor modulation
- Magnesium citrate + taurate + malate broaden the cofactor coverage for energy metabolism and cardiovascular support
- 3000 mg glycine (added beyond the glycinate itself) mildly lowers core body temperature, a prerequisite for falling asleep
- Zinc contributes to normal cognitive function and supports the nightly recovery window
- Chamomile + lemon balm are traditional calming botanicals with long use in evening wind-down rituals
Heey! Rest & Recover uses this stack by design, not as separate products.
Which Heey! magnesium fits you?
| Product | Price | Key actives | Fits you if |
|---|---|---|---|
| Rest & Recover | 259 kr | 4-form magnesium complex (225 mg) + 3000 mg glycine + zinc + chamomile + lemon balm. Strawberry Lemonade. | You want the sleep / stress / recovery stack. Evening routine, calming, non-laxative. |
| Hydrate & Glow | 279 kr | Magnesium glycinate 75 mg + electrolytes + vegan collagen | You want smaller daily magnesium as part of hydration, plus beauty support. |
| Hydrate & Focus | 279 kr | Magnesium bisglycinate 75 mg + electrolytes + lion's mane + bacopa + B-vitamins | Daytime magnesium stacked with mental-energy actives. |
Frequently asked questions
Q: Is magnesium glycinate really that much better than oxide?
A: Yes, by roughly a factor of ten in absorption. Oxide absorbs at ~4%, glycinate at ~40%. That's why a 100 mg glycinate dose often outperforms a 400 mg oxide dose for sleep, stress, or muscle function.
Q: What's the difference between glycinate and bisglycinate?
A: They're the same compound. "Bisglycinate" makes the chelate structure explicit — two glycine molecules bound to one magnesium. Both terms are used interchangeably on labels. Heey! products use both terms depending on raw-material supplier.
Q: Why does magnesium oxide cause diarrhea?
A: Only ~4% absorbs. The remaining 96% sits in the gut, pulls water in osmotically, and triggers loose stools. This is why oxide is sold over the counter as a laxative — it's the same compound at a slightly higher dose.
Q: Can I take magnesium glycinate every day?
A: Yes, at label doses. EFSA's tolerable upper intake from supplements is 250 mg elemental magnesium per day in addition to dietary intake. Heey! Rest & Recover is formulated within safe daily ranges. Always follow the label.
Q: Should I take magnesium in the morning or at night?
A: Depends on form and goal. Glycinate for sleep: 30-60 min before bed. Glycinate for stress during the day: any time. Malate: morning or pre-training. Citrate or oxide for constipation: morning.
Q: Does magnesium glycinate help with anxiety?
A: The evidence is moderate. A 2017 Nutrients review concluded magnesium supplementation "appears to have a beneficial effect on subjective anxiety" in anxiety-vulnerable populations. Glycinate is the form most used in that context because of tolerability and the calming glycine co-factor.
Q: What's in Heey! Rest & Recover besides magnesium?
A: Beyond the four magnesium forms (bisglycinate + citrate + taurate + malate), the formula adds 3000 mg glycine for sleep-onset support, zinc for cognitive and recovery support, plus chamomile and lemon balm as traditional calming botanicals. The combination is built around the evening routine, not just the mineral.
Q: Can I take magnesium glycinate with food?
A: Yes. Food slightly slows absorption but doesn't reduce total uptake. Some people find taking it with a small meal reduces any residual stomach sensitivity.
Q: What about magnesium threonate or taurate — are they better?
A: Magnesium L-threonate is a newer form with some cognitive-focused research, but high cost and limited evidence base. Taurate is less studied. For sleep, stress, and daily use, glycinate remains the best-evidenced non-laxative form.
Q: How do I know a product contains glycinate and not oxide?
A: Read the ingredient list — the exact form must be declared in the EU. If you see only "magnesium" with a milligram value, assume oxide. If you see "magnesium bisglycinate," "magnesium citrate," or similar, the form is disclosed. Heey! products list the specific form on every label.
Why Heey!'s magnesium?
- Magnesium glycinate / bisglycinate, the highest-absorption form, no laxative side effect
- 4-form magnesium complex in Rest & Recover, bisglycinate + citrate + taurate + malate for broader cofactor coverage
- 3000 mg glycine + zinc + chamomile + lemon balm, supporting cofactors for evening wind-down
- 100% vegan, no gelatin, standard across Heey!'s range
- Made in Sweden, transparent manufacturing, EU supplement standards
- No added sugar, standard across all Heey! products
- Strawberry Lemonade flavor, drinkable like an evening tea, 30 servings per pouch
- 4.8★ average from 1000+ verified reviews across Heey!'s full range
Next step
See all Heey! magnesium products →
Or go straight to the right product for you: Rest & Recover 259 kr (4-form magnesium complex + calming cofactors for sleep and stress) or the Hydrate & Glow 279 kr variant if you want magnesium as part of daily hydration.
Remember: 10% on us, use code HEEY10 at checkout on your first order.
